Preliminary DMR measurements of the CMB isotropy

Conference · Mon Apr 15 00:00:00 EDT 1991 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:5399407

Smoot, G F ^[1]; Bennett, C L ^[2]; Kogut, A ^[3]; Aymon, J ^[4]; Backus, C ^[5]; De Amici, G ^[4]; Galuk, K; Jackson, P D; Keegstra, P; Rokke, L ^[5]; Tenorio, L ^[4]; Gulkis, S ^[6]; Hauser, M G ^[7]; Janssen, M ^[6]; Mather, J C ^[8]

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1. Lawrence Berkeley Laboratory, CA (United States) Space Sciences Laboratory, University of California, Berkeley (USA)
2. Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center (USA)
3. National Research Council, NASA/GSFC (USA)
4. Lawrence Berkeley Laboratory and Space Sciences Laboratory, University of California, Berkeley (USA)
5. ST Systems Inc (USA)
6. NASA Jet Propulsion Laboratory, Pasadena (USA)
7. Laboratory for Astronomy and Solar Physics, NASA Goodard Space Flight Center (USA)
8. Laborator

The COBE Differential Microwave Radiometers (DMR) instrument has produced preliminary full-sky maps at frequencies 31.5, 53, and 90 GHz. The redundant channels and matched beams at three frequencies distinguish the DMR from previous large-scale surveys. Galactic emission is seen unambiguously at all three frequencies. The only large-scale anisotropy detected in the cosmic microwave background is the dipole anisotropy. There is no clear evidence for any other large-angular-scale feature in the maps. Without correcting for any systematic effects, we are able to place limits {Delta}T/T{sub 0}{lt}3{times}10{sup {minus}5} for the rms quadrupole amplitude, {Delta}T/T{sub 0}{lt}4{times}10{sup {minus}5} for monochromatic fluctuations, and {Delta}T/T{sub 0}{lt}4{times}10{sup {minus}5} for Gaussian fluctuations (all limits are 95% C.L. with T{sub 0}=2.735 K). The data limit {Delta}T/T{sub 0}{lt}10{sup {minus}4} for any feature larger than 7{degree}. We briefly review the DMR and discuss some implications of these results for cosmology.

• OSTI ID: 5399407
• Report Number(s): CONF-9010268--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 222:1
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
BACKGROUND RADIATION
BOSONS
COSMIC PHOTONS
COSMIC RADIATION
DATA PROCESSING
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FLUCTUATIONS
GAUSSIAN PROCESSES
IONIZING RADIATIONS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
MEASURING METHODS
MICROWAVE RADIATION
MULTIPOLES
PHOTONS
PROCESSING
RADIATION DETECTORS
RADIATIONS
RADIOMETERS
SPHERICAL HARMONICS METHOD
TEMPERATURE MEASUREMENT
VARIATIONS